This motorized spinning rock is a commissioned work of art by Zachary Coffin.  I performed the mechanical design and engineering analysis for the spinning base that supports the stone. A motor and custom gear train slowly spin the stone using energy from a solar panel. A decoupling mechanism allows the stone to be spun by hand at anytime without resistance from the motor. A very fun piece for children and adults alike. There's nothing that compares to the superhuman feeling of moving a boulder.
It is on display at the Atlanta Botanical Gardens, Sculptures in Motion art show.
The following article is from the Atlanta Journal and Constitutiion ( website: